Question : How many days should you spend in Tokyo if you're flying in from Dallas?
Answer : Of course you're not most people, but if you were, you'd stay roughly 18 days.
Question : Would you be willing to change your travel days if it saved you money?
Answer : For the month of December, the cheapest day to fly is Friday. Flexibility is paramount when booking travel plans in order to keep costs down.
Question : Are prices changing frequently for this route?
Answer : Prices are fluctuating much more for this route than most routes. The further out you book a route, the more likely you are to save.